Pressing tool

ABSTRACT

The invention relates to a pressing tool ( 8 ) provided with three or four press mandrels ( 12, 15 ) which move towards each other during the pressing process. The press mandrels ( 12 - 15 ) have a roof-shaped transversal profile. The lateral distance ( 36 ) between the press mandrels (12-15) is increasingly reduced during the pressing process. An extending element ( 37 ) is arranged between two press mandrels, extending from one press mandrel to another press mandrel and being inserted into the other press mandrel during the pressing process. The aim of the invention is to improve said pressing device and to improve pressing. In order to block the above-mentioned distance ( 36 ), the extending element ( 37 ) is disposed in such a way that both roof edges ( 38 ) of the corresponding press mandrels cut across said extending element ( 37 ) in an initial position.

[0001] The invention relates, in the first instance, to a pressing toolwith three or four pressing mandrels which can be moved towards oneanother during a pressing process, it being the case that the pressingmandrels have a roof-like cross-sectional profile, and that,furthermore, a lateral clearance space between the pressing mandrels isincreasingly reduced during a pressing process, and disposed between twopressing mandrels is an extension element which extends from onepressing mandrel to the other and moves into the other pressing mandrelduring pressing.

[0002] Such pressing tools are known and serve, inter alia, forconnecting a cable end to a cable eye, two or three of the pressingmandrels being displaced, by means of hydraulic actuation, in thedirection of the centre of the pressing space during the pressingprocess. In this respect, for example, a four-mandrel pressing tool isknown from Canadian patent 679 495 which has a fixed pressing mandreland three further pressing mandrels which can be displaced to the centreof a pressing space, in each case one extension element being disposedin the region of the lateral clearance spaces between the displaceablepressing mandrels, for the purpose of guiding the pressing jaws carryingthe pressing mandrels. The problem with the known pressing tools isthat, between being placed in position and actually being pressed, theblank, for example the cable eye accommodating a cable end, changes itsposition to the extent where unsuccessful pressing is achieved.

[0003] In respect of the abovedescribed prior art, it is a problem ofthe invention for a pressing tool of the type in question to bedeveloped in an advantageous manner in particular in respect of animproved pressing result.

[0004] This problem is solved first and foremost by the subject matterof claim 1, this being based on the fact that the extension element, forthe purpose of blocking the clearance space, is arranged such that, inthe initial state, the two roof edges of the associated pressingmandrels cut across the extension element. As a result of thisconfiguration according to the invention, the blank which is to beplaced in position and pressed is supported at such a level that, as thepressing mandrels are moved towards it, self-centring of the blankbetween these mandrels is achieved. The pressing sleeve of a cable eyeis thus always located entirely in the region of action of the pressingmandrels, so that precise, successful pressing of the cable eye andcable end is always achieved. The extension element here is positionedsuch that a blank which is not positioned centrally in the pressingspace is always forced into the desired pressing position by theextension element during the pressing process. In this case, anextension element is disposed between two pressing mandrels such thatthe respectively facing edge of the pressing mandrel, at least inprolongation of the same, cuts across the extension element.Furthermore, the arrangement of the extension element is selected suchthat the blank which is to be pressed, in an original arrangement in theregion of the lateral clearance space between two pressing mandrels,encloses an angle, between a perpendicular to the direction in which theblank is advanced out of the clearance space and a bearing point on anoblique surface of a pressing mandrel, which is larger than the angle offriction, this achieving the desired advancement of the eccentricallypositioned blank between the pressing mandrels during pressing. In apreferred configuration, extension elements disposed according to theinvention pass through two of the three lateral clearance spaces, in apressing tool with three mandrels, and through three of the fourclearance spaces, in the case of a pressing tool with four pressingmandrels.

[0005] It may also be provided that the fixed pressing mandrel isfastened on a pivoting bracket, by means of which the radial access tothe pressing space can be blocked. Following placement and closure ofthe pivoting bracket, the latter is preferably locked in a positivemanner. In order to achieve an improved pressing result, in the case ofa four-mandrel pressing tool of the type in question, it being the casethat the pressing mandrels have a roof-like cross-sectional profile, andthat, furthermore, a lateral clearance space between the pressingmandrels is increasingly reduced during a pressing process, and disposedbetween two pressing mandrels is an extension element which extends fromone pressing mandrel to the other and moves into the other pressingmandrel during pressing, it is proposed that the extension element, forthe purpose of blocking the clearance space, is disposed such that, inthe initial state, the two roof edges of the associated pressingmandrels cut across the extension element. As a result of thisconfiguration according to the invention, the blank which is to beplaced in position and pressed is supported at such a level that, as thepressing mandrels are moved towards it, self-centring of the blankbetween these mandrels is achieved. The pressing sleeve of a cable eyeis thus always located entirely in the region of action of the pressingmandrels, so that precise, successful pressing of the cable eye andcable end is always achieved. The extension element here is positionedsuch that a blank which is not positioned centrally in the pressingspace is always forced into the desired pressing position by theextension element during the pressing process. In this case, anextension element is disposed between two pressing mandrels such thatthe respectively facing edge of the pressing mandrel, at least inprolongation of the same, cuts across the extension element.Furthermore, the arrangement of the extension element is selected suchthat the blank which is to be pressed, in an original arrangement in theregion of the lateral clearance space between two pressing mandrels,encloses an angle, between a perpendicular to the direction in which theblank is advanced out of the clearance space and a bearing point on anoblique surface of a pressing mandrel, which is larger than the angle offriction, this achieving the desired advancement of the eccentricallypositioned blank between the pressing mandrels during pressing.Disposing the fixed pressing mandrel on a pivoting bracket whichreleases the pressing space advantageously makes it possible for twoextension elements projecting in opposite directions to be fitted on thefixed pressing mandrel. As a result of this configuration, in the closedstate of the pivoting bracket, that is to say with the pressing spaceclosed, extension elements disposed according to the invention passthrough all the clearance spaces produced between the four pressingmandrels. Irrespective of whether a pressing tool with a radialpressing-space opening or a four-mandrel tool with a fixed pressingmandrel fastened on a pivoting bracket is present, it is furtherproposed that an edge of the extension element which is directed towardsthe pressing space, on the two associated pressing mandrels, runsdirectly beneath the roof edge. As a result of this arrangement, atleast in the initial state, and preferably also over much of thedisplacement path of the pressing mandrels, trapezoidal surfaces aredefined in the region of the clearance space, the top lines of thesesurfaces connecting the roof ridges of two adjacent pressing mandrelsand the bottom lines thereof being formed by that edge of the extensionelement which is directed towards the pressing space. The side lines ofthe trapezoidal surfaces are substantially formed by the two roof edgesof the associated pressing mandrels, the length of the trapezium sidelines corresponding to the length of a roof edge. As an alternative, itis also possible for the length of this trapezium side line tocorrespond to 1.1 to 1.3 times the roof-edge length. The significantfactor here is for the trapezium side line to be smaller than 1.5 timesthe roof-edge length. In an exemplary configuration of the subjectmatter of the invention, it may be provided that an extension element isformed integrally with one pressing mandrel and moves into acorresponding recess of the other pressing mandrel. The extensionelement may thus be formed as a supplementary supporting surface of thepressing mandrel, in which case the supplementary supporting surfaces oftwo adjacent pressing mandrels overlap as they are moved together and,in the extended state, that is to say in the initial state, close theclearance space between the two adjacent pressing mandrels at least tothe extent where a cable eye of conventional diameter cannot passthrough. In this respect, it is further proposed that an edge of theextension element which is directed towards the pressing space runs intothe eaves of the roof of the pressing mandrel, this edge of theextension element also being inclined preferably approximately to thesame extent as the remote roof edge of the associated pressing mandrel.Furthermore, it is preferably provided that the extent of the integrallyformed extension element is less than the width of the roof. A preferredconfiguration is one in which the extent of the integrally formedextension element is less than half the width of the roof. It isadvantageously further provided that two adjacent pressing mandrels eachhave an integrally formed extension element, the extension elementsalternately projecting towards one another. In this case, each extensionelement is assigned, laterally adjacent to it, a recess for theintroduction of the extension element of the adjacent pressing mandrel.As a result of this configuration, it is ensured that the extensionelements, which shift the blank, for example the cable eye, into thecorrect position, do not enter into the pressing space. Accordingly,only the pressing mandrels with the roof-like cross-sectional profileare active during pressing. It is also provided that the associatedextension elements are offset depthwise in relation to one another. Asan alternative to the pressing mandrel and extension element beingformed in one piece, it may also be provided that an extension elementis formed by a rod-like element which is anchored in one pressingmandrel and is accommodated in a freely movable manner in the otherpressing mandrel. For this purpose, the other, adjacent pressing mandrelhas, for example, a bore into which the extension element can penetrateduring the pressing operation and the accompanying displacement of thepressing mandrels and/or of the pressing jaws carrying the latter. Inthis respect, it is further provided that the extension element is around rod, which may furthermore also be in the form of a needle. Inaddition, it is provided that two rod-like extension elements are offsetin relation to one another. These are thus, further preferably, offsetdepthwise in relation to one another, so that the extension elements actin adjacent planes. As a further alternative, it may be provided thatthe extension element is attached to a side surface of the pressingmandrel, and/or of the pressing jaw carrying the pressing mandrel, andmoves past the side surface of the adjacent pressing mandrel duringpressing. It is thus further preferably provided that two oppositelylocated extension elements are fastened on a pressing mandrel. Theseextension elements attached on both sides of the pressing mandrel areadvantageously formed symmetrically here, it being possible for anextension element to be in the form of a sheet-metal angle element. Asan alternative the extension element may also be in the form of a bentwire part.

[0006] The invention is explained in more detail hereinbelow withreference to accompanying drawings, which merely illustrate a number ofexemplary embodiments and in which:

[0007]FIG. 1 shows, in a perspective illustration, a hydraulic implementwhich is operated by an electric motor and has an associated pressingtool according to the invention;

[0008]FIG. 2 shows a further perspective illustration of a hydraulicimplement in the form of a manually operated implement with a pressingtool according to the invention;

[0009]FIG. 3 shows a partially longitudinally sectioned pressing tool inthe initial state, relating to a first embodiment;

[0010]FIG. 4 shows a sectional illustration corresponding to FIG. 3, butin a section through a plane adjacent to FIG. 3;

[0011]FIG. 5 shows the pressing tool of the first embodiment in aperspective illustration on its own;

[0012]FIG. 6 shows the enlargement of the region VI-VI in FIG. 4;

[0013]FIG. 7 shows an illustration corresponding to FIG. 4, but relatingto the pressing position;

[0014]FIG. 8 shows an illustration corresponding to FIG. 3, but relatingto a second embodiment of the pressing tool;

[0015]FIG. 9 shows a section through a plane adjacent to FIG. 8;

[0016]FIG. 10 shows a perspective exploded illustration of the pressingtool according to the second embodiment;

[0017]FIG. 11 shows the enlargement of the region XI-XI in FIG. 9;

[0018]FIG. 12 shows a further enlargement, but this time relating to anintermediate position of the pressing mandrels of the pressing toolduring the pressing operation;

[0019]FIG. 13 shows an illustration corresponding to FIG. 9, butrelating to the pressing position;

[0020]FIG. 14 shows the pressing tool in partially longitudinallysectioned illustration, relating to a third embodiment;

[0021]FIG. 15 shows the longitudinal section adjacent to FIG. 14;

[0022]FIG. 16 shows the enlargement of the region XVI-XVI in FIG. 15;

[0023]FIG. 17 shows a further illustration corresponding to FIG. 3,relating to a fourth embodiment of the pressing tool;

[0024]FIG. 18 shows the enlargement of the region XVIII-XVIII in FIG.17;

[0025]FIG. 19 shows a perspective exploded illustration of the pressingtool according to FIG. 17;

[0026]FIG. 20 shows a further perspective exploded illustration of apressing tool in a fifth embodiment;

[0027]FIG. 21 shows a sectional illustration, corresponding to FIG. 3,of a pressing tool in a sixth embodiment;

[0028]FIG. 22 shows the enlargement of the region XXII-XXII in FIG. 21;

[0029]FIG. 23 shows the perspective exploded illustration of thepressing tool in FIG. 21;

[0030]FIG. 24 shows a view of a pressing tool in a seventh embodiment,with a pivoting bracket retained in the open position;

[0031]FIG. 25 shows a partial sectional illustration corresponding toFIG. 3, relating to the embodiment according to FIG. 24;

[0032]FIG. 26 shows a sectional illustration of the pressing tool, thesection plane being offset in relation to that of FIG. 25;

[0033]FIG. 27 shows the enlarged region XXVII-XXVII in FIG. 26.

[0034] A hydraulic implement 1 in the form of a pressing implement,which is operated by an electric motor, will be illustrated anddescribed in the first instance with reference to FIG. 1. Such apressing implement is known from German Patent Application 198 25 160.2.Reference is also made to German Patent Application 197 43 747. Thecontent of these patent applications are hereby included in full in thedisclosure of the present invention, also for the purpose of includingfeatures of these patent applications in claims of the presentinvention.

[0035] An electric motor is disposed in the implement 1. This electricmotor is driven via a storage battery 3 integrated in a handgrip 2.Actuation of a finger-actuable switch 5 causes oil to be pumped from asupply container into a pressure space, as a result of which a hydrauliccylinder is moved, counter to the action of a restoring spring, in thedirection of its operating end position.

[0036] The hydraulic cylinder is moved back via a restoring spring assoon as a non-return value opens on account of a predetermined maximumpressure being exceeded.

[0037] The implement illustrated in FIG. 2 is in the form of a manuallyactuable implement. Accordingly, the pressure required for displacingthe hydraulic cylinder is built up by manual actuation, via a pumpinglever 6, rather than by an electric motor.

[0038] Irrespective of the formation of the implement 1, the latter hasa neck 7 which encloses the hydraulic cylinder (not illustratedspecifically) and on which a pressing tool 8 can be disposed. Thearrangement of the securing head 9 of the pressing tool 8 on the neck 7is preferably chosen such that the securing head 9, and thus thepressing tool 8, can be rotated about the neck axis.

[0039] Irrespective of the embodiments described hereinbelow, thepressing tool 8 substantially comprises two shell-like housing parts 10,11 which, screw-connected to one another, leave an accommodating spacebetween them for the purpose of accommodating four pressing jaws 16 to19 each provided with a pressing mandrel 12 to 15 (see, in this respect,for example the illustration in FIG. 10).

[0040] In a known manner here, the pressing jaw 16 is mounted forsliding action in the housing along the longitudinal extent of thepressing tool 8 and has the hydraulic piston of the implement 1 actingon it from the rear during the pressing operation.

[0041] Opposite the surface on which the hydraulic piston acts, theassociated pressing mandrel 12 is formed on the pressing jaw 16,disposed on the hydraulic-piston axis in the operating position. Thispressing mandrel, just like the further pressing mandrels 13 to 15 whichare yet to be described, has a circular outline in plan view with aroof-like cross-sectional profile, the roof ridge 20 being orientedtransversely to the displacement direction of the pressing jaw.

[0042] Above and beneath the pressing mandrel 12, the pressing jaw 16 isprovided with wedge-shaped notches, the wedge surfaces 21, which aredirected away from the pressing mandrel 12, interacting withcorrespondingly oriented wedge surfaces 22 of the pressing jaws 17 and18. Rolling-contact bearings 23 are disposed between the wedge surfaces21 and 22.

[0043] Furthermore, in the region of the continuation 24 formed by thecutouts, and carrying the pressing mandrel 12, guide pins 25 whichextend parallel to the wedge surfaces 21 are anchored on both sides, theother ends of these guide pins penetrating into correspondingly orientedbores 26 of the pressing jaws 17 and 18. Positioned between the pressingjaws 17, 18 and the continuation 24 of the pressing jaw 16 in each caseis a compression spring 27, which surrounds the associated guide pin 25.

[0044] On the side which is directed away from the continuation 24 ofthe pressing jaw 16, furthermore, the pressing jaws 17, 18 have acontrol surface 28, which runs at right angles to their wedge surface 22and, assisted by the compression spring 27, engages against a guideroller 29 which is mounted in a rotatable manner on the housing.

[0045] The mutually facing surfaces 30, 31 of the pressing jaws 17, 18and of the continuation 24—in relation to a longitudinally sectionedillustration according to FIG. 3—are oriented parallel to a displacementaxis x which runs in extension of the hydraulic-piston axis.

[0046] The pressing mandrels 13, 14 are oriented towards one another, atright angles to the pressing mandrel 12, on the surfaces 30 of thepressing jaws 17, 18.

[0047] The fourth pressing jaw 19 is anchored in the housing, and isthus fixed, the pressing mandrel 15 thereof, oriented along the axis x,facing in the direction of the opposite pressing mandrel 12 of thedisplaceable pressing jaw 16.

[0048] In the initial state of the pressing tool 8, the pressingmandrels 12 to 15 are spaced apart uniformly from one another. Thepressing space 34 described here is open on both sides by way ofcorresponding recesses 32 in the housing parts 10, 11. These recesses 32are open radially outwards in the direction of an end side of thepressing tool 8, an introduction channel 33 being formed as a result.Starting from the end side of the pressing tool 8, this introductionchannel substantially extends between the fixed pressing mandrel 15 anda pressing mandrel 14 disposed perpendicularly thereto. As a result ofthis configuration, it is possible for a cable end which is to bepressed, for example, with a cable eye to be introduced through theintroduction channel 33 into the pressing space 34 bounded by thepressing mandrels 12 to 15.

[0049] During a pressing operation, in the case of which the hydraulicpiston of the implement 1 engages against the rear of the pressing jaw16, this pressing jaw 16 with the pressing mandrel 12 is displaced,along the pressing axis x, in the direction of the fixed pressingmandrel 15 located opposite, which at the same time, via the wedgesurfaces 21 and 22—with the roller-contact bearings providedtherebetween—and via the control surface 28 supported on the guideroller 29, causes the pressing jaws 17 and 18 to be displaced. Thisdisplacement of the pressing jaws 17, 18 takes place both parallel tothe displacement of the pressing jaw 16 and, at the same time, in theperpendicular direction, so that the three movable pressing mandrels 12to 14 move uniformly in the direction of the fixed pressing mandrel 15,with the blank, for example cable eye 35, which is positioned in thepressing space 34 being pressed uniformly in the process.

[0050] Once pressing has taken place, that is to say once apredetermined pressing pressure has been exceeded, the hydraulic piston,as has been described, moves back automatically into the startingposition. The pressing jaws follow the hydraulic piston on account ofthe compression springs 27, which are compressed during pressing, beingrelieved of stressing, the pressing jaws 17, 18 being carried along viathe guide pins 25 anchored in the pressing jaw 16.

[0051] In order for the cable eye 35 which is to be pressed, and ispositioned in the pressing space 34, to be prevented from sliding intothe lateral clearance spaces 36 which are located between the pressingmandrels and are increasingly reduced during the pressingoperation—which sliding action could possibly result in unsuccessfulpressing—various solutions are presented by the embodiments which aredescribed in more detail hereinbelow.

[0052] Common to all the embodiments illustrated is the fact that twopressing mandrels 12 and 13, 12 and 14 and also 13 and 15 have disposedbetween them in each case an extension element 37 which extends from onepressing mandrel to the other, the extension element 37 being anchoredon one pressing mandrel and moving into the other pressing mandrelduring pressing. According to the invention, the extension elements 37,for the purpose of blocking the clearance space 36, are disposed suchthat, both in the initial state and during the pressing operation, thetwo associated roof edges 38 of the pressing mandrels bounding theclearance space 36 cut across the extension element 37, it being thecase, furthermore, that the edge 39 of the extension element 37 which isdirected towards the pressing space 34, on the two associated pressingmandrels, runs directly beneath the roof edge 38. This results in theformation of a trapezoidal surface T which is bounded by the facingedges 38 of the associated pressing mandrels and that edge of theextension element 37 which is directed towards the pressing space 34 andalso by an imaginary line connecting the roof ridges 20 of theassociated pressing mandrels, the side boundary lines of the trapezoidalsurface corresponding to 1 to 1.3 times the roof-edge length. As aresult of this configuration, the blank, for example the cable eye 35,is always forced in the direction of the pressing space 34 during thepressing operation, that is to say during the advancement of thepressing mandrels 12 to 14 in the direction of the pressing mandrel 15,so that the blank is present in the correct position between thepressing mandrels 12 to 15 during pressing.

[0053] In the first exemplary embodiment, which is illustrated in FIGS.3 to 7, the extension element 37 is formed integrally with a pressingmandrel 12 to 15, in order to form a supplementary supporting surface.Each pressing mandrel 12 to 15 has a protrusion-like extension element37 in each case assigned to each roof edge 38, the two extensionelements 37 of a pressing mandrel being disposed in offset planes in thedirection in which the roof ridge 20 extends. Recesses 40 are providedon one side adjacent to these extension elements 37, extension elements37 of the adjacent pressing mandrels moving into these recesses duringthe pressing operation, and the extension elements 37 of two adjacentpressing mandrels projecting alternately towards one another in eachcase.

[0054] The edge 39 of the integrally formed extension element 37, thisedge being directed towards the pressing space 34, runs approximatelyparallel to the remote roof edge 38 of the associated pressing mandrel,this edge 39 furthermore running into the eaves 41 of the roof of thefacing roof edge 38 of the pressing mandrel (see FIG. 6).

[0055] The extension elements 37, which overlap when the pressingmandrels are moved together, close the clearance space 36, which isformed between the pressing mandrels, to the extent where theconventional-diameter blank cannot pass between the extension elements37 into the clearance space 36. The extent a of the integrally formedextension element 37 is thus selected to be less than half the width bof the pressing-mandrel roof.

[0056] As an alternative, the extension element 37 may be formed in arod-like manner as a round rod 42 (see second embodiment in FIGS. 8 to13) or as a needle 43 (see third embodiment in FIGS. 14 to 16). Theserod-like extension elements 37—round rod 42 or needle 43—are anchored inone of the pressing mandrels and accommodated in a freely movable mannerin the other associated pressing mandrel.

[0057] It is thus the case in the third and fourth exemplary embodimentsillustrated that two rod-like extension elements 37 projecting inopposite directions are anchored in the continuation 24, which carriesthe pressing mandrel 12. These extension elements each pass through theadjacent clearance space 36 and penetrate into correspondingly formedguide bores 44 of the pressing jaws 17 and 18, which carry the pressingmandrels 13 and 14, respectively. Here too, the extension elements 38are offset depthwise in relation to one another, that is to say they aredisposed in offset planes.

[0058] Furthermore, a rod-like extension element 37 is anchored in thefixed pressing jaw 19, which carries the pressing mandrel 15, thisextension element likewise penetrating into a guide bore 44 of thepressing jaw 17, which carries the pressing mandrel 13, and blocks theadjacent clearance space 36 in the operation.

[0059] In the second embodiment illustrated according to FIGS. 8 to 13,the diameter of the guide bores 44 corresponds to the diameter of theround rod 42 forming the extension element 37. In contrast, in the thirdexemplary embodiment, which is illustrated in FIGS. 14 to 16, thediameter of the needle 43 forming the extension element 37 isconsiderably smaller than the diameter of the guide bore 44, for whichpurpose the needle 43 has a sliding head 45 arranged, for guidancepurposes, in the region of the guide bore 44.

[0060] Disposing the rod-like extension elements 37 directly beneath theroof edges 38 results in the cable eye 35 which is to be pressedenclosing an angle alpha, between a perpendicular S to the advancementdirection u of the cable eye 35 and a bearing point P on a roof edge 38,which is larger than the angle of friction, this achieving the desiredadvancement of the eccentrically positioned cable eye 35 between thepressing mandrels during pressing. An angle alpha of 15 degrees isprovided in the exemplary embodiment illustrated (see FIG. 12).

[0061] As can further be gathered from the drawings of FIGS. 17 to 20,which illustrate a fourth and a fifth embodiment, the extension elements37 may also be in the form of bent wire parts 46 which are disposedlaterally opposite one another on the pressing mandrel 12 or pressingjaw 16 and the angled free legs of which block the clearance spaces 36between the pressing mandrel 12 and the pressing mandrel 13 and betweenthe pressing mandrel 12 and the pressing mandrel 14, as a result ofwhich the blank is always forced into the correct pressing position bythe wire legs. The sectional illustration in FIG. 17 shows anintermediate position during the pressing operation.

[0062] Furthermore, according to the sixth embodiment, the extensionelement 37 may be in the form of a sheet-metal angle element 47, theselikewise being disposed opposite one another on both sides of thepressing mandrel 12 or of the pressing jaw 16 and, in the same way asthe previously described bent wire parts 46, having symmetrically formedlegs for forming the extension elements 37.

[0063] Finally, FIGS. 24 to 27 show a seventh embodiment, in the case ofwhich the fixed pressing mandrel 15, and the pressing jaw 19 thereof, isfastened on a pivoting bracket 48, which is mounted in a pivotablemanner on the housing and by means of which the radial access to thepressure space 34 can be blocked. For this purpose, the housing parts 10and 11 have an approximately U-shaped outline in plan view, theU-opening forming the pressing space 34. The pivoting bracket 48 ismounted on one U-leg such that it can be rotated about an axis y. Theother, free end of the pivoting bracket 48 can be latched in the regionof the opposite U-leg of the housing, it being possible for thislatching action to be cancelled by means of a handle 49 (not illustratedspecifically).

[0064] Fitted on the fixed pressing mandrel 15, which is fastened on thepivoting bracket 48, are two extension elements 37 in the form of roundrods 42, which project in opposite directions and, in the closed stateof the pressing tool 8 according to FIGS. 25 and 26, penetrate intocorrespondingly associated guide bores 44 of the adjacent pressingmandrels 13, 14. The pressing space 34, which is fully enclosed by apivoting bracket 48 being provided according to the invention, issurrounded, then, by four extension elements 37 which block all theclearance spaces 36 formed between the pressing mandrels.

[0065] All features disclosed are (in themselves) pertinent to theinvention. The disclosure content of the associated/attached prioritydocuments (copy of the prior application) is hereby also included infull in the disclosure of the application, also for the purpose ofincorporating features of these documents in claims of the presentapplication.

1. Pressing tool (8) with three or four pressing mandrels (12-15) whichcan be moved towards one another during a pressing operation, thepressing mandrels (12-15) having a roof-like cross-sectional profile,and thus, furthermore, a lateral clearance space (36) between thepressing mandrels (12-15) is increasingly reduced during a pressingoperation, and disposed between two pressing mandrels is an extensionelement (37) which extends from one pressing mandrel to the other andmoves into the other pressing mandrel during pressing, characterized inthat the extension element (37), for the purpose of blocking theclearance space (36), is disposed such that, in the initial state, thetwo roof edges (38) of the associated pressing mandrels cut across theextension element (37).
 2. Pressing tool according to claim 1 or inparticular according thereto, it being the case that one pressingmandrel (15) is fixed and the three further pressing mandrels can bedisplaced in the direction of the centre of a pressing space (34) duringa pressing operation, characterized in that the fixed pressing mandrel(15) is fastened on a pivoting bracket (48), by means of which theradial access to the pressing space (34) can be blocked.
 3. Pressingtool according to claim 2 or in particular according thereto, it beingthe case that the pressing mandrels (12-15) have a roof-likecross-sectional profile, and thus, furthermore, a lateral clearancespace (36) between the pressing mandrels (12-15) is increasingly reducedduring a pressing operation, and disposed between two pressing mandrelsis an extension element (37) which extends from one pressing mandrel tothe other and moves into the other pressing mandrel during pressing,characterized in that the extension element (37), for the purpose ofblocking the clearance space (36), is disposed such that, in the initialstate, the two roof edges (38) of the associated pressing mandrels cutacross the extension element (37).
 4. Pressing tool according to eitherof claims 2 and 3 or in particular according thereto, characterized inthat two extension elements (37) projecting in opposite directions arefitted on the fixed pressing mandrel (15).
 5. Pressing tool according toone or more of the preceding claims or in particular according thereto,characterized in that an edge (35) of the extension element (37) whichis directed towards the pressing space (34), on the two associatedpressing mandrels, runs directly beneath the roof edge (38).
 6. Pressingtool according to one or more of the preceding claims or in particularaccording thereto, characterized in that an extension element (37) isformed integrally with one pressing mandrel (12-15) and moves into acorresponding recess (40) of the other pressing mandrel.
 7. Pressingtool according to one or more of the preceding claims or in particularaccording thereto, characterized in that an edge (35) of the extensionelement (37) which is directed towards the pressing space (34) runs intothe eaves (41) of the roof of the pressing mandrel (12-15).
 8. Pressingtool according to one or more of the preceding claims or in particularaccording thereto, characterized in that the extent (a) of theintegrally formed extension element (37) is less than the width (b) ofthe roof.
 9. Pressing tool according to one or more of the precedingclaims or in particular according thereto, characterized in that theextent (a) of the integrally formed extension element (37) is less thanhalf the width (b) of the roof.
 10. Pressing tool according to one ormore of the preceding claims or in particular according thereto,characterized in that two adjacent pressing mandrels each have anextension element (37) formed thereon, the extension elementsalternately projecting towards one another.
 11. Pressing tool accordingto one or more of the preceding claims or in particular accordingthereto, characterized in that the associated extension elements (37)are offset depthwise in relation to one another.
 12. Pressing toolaccording to one or more of the preceding claims or in particularaccording thereto, characterized in that an extension element (37) isformed by a rod-like element which is anchored in one pressing mandrel(12, 15) and is accommodated in a freely movable manner in the otherpressing mandrel (17, 18).
 13. Pressing tool according to one or more ofthe preceding claims or in particular according thereto, characterizedin that the extension element (37) is a round rod (42).
 14. Pressingtool according to one or more of the preceding claims or in particularaccording thereto, characterized in that two rod-like extension elements(37) are offset in relation to one another.
 15. Pressing tool accordingto one or more of the preceding claims or in particular accordingthereto, characterized in that the extension element (37) is attached toa side surface of the pressing mandrel (12) and moves past the sidesurface of the adjacent pressing mandrel (13, 14) during pressing. 16.Pressing tool according to one or more of the preceding claims or inparticular according thereto, characterized in that two oppositelylocated extension elements (37) are fastened on a pressing mandrel (12).17. Pressing tool according to one or more of the preceding claims or inparticular according thereto, characterized in that an extension element(37) is in the form of a sheet-metal angle element (47).
 18. Pressingtool according to one or more of the preceding claims or in particularaccording thereto, characterized in that an extension element (37) is inthe form of a bent wire part (46).